The mechanism of enzyme secretion is being studies using as models the formation and secretion of invertase by the eukaryote yeast (Saccharomyces) and of penicillinase by the prokaryote Bacillus licheniformis. As adequate quantities of the external mannan-protein form of invertase and of the internal carbohydrate-free enzyme become available, their subunit structures will be compared to clarify their biosynthetic relationship. The role of the glycosylation process in controlling formation of the polypeptide portion of the enzyme is being investigated utilizing inhibitors of RNA and protein synthesis and of glucosamine metabolism as biochemical tools. Chemical characterization of the lipophilic membrane bound penicillinase will be continued, especially to determine the nature of the phospholipid-like moiety associated with the enzyme and if a covalent phospholipid-protein linkage is present. The releasing factor (apparently associated with the periplasmic vesicle (mesosome?) fraction that converts the membrane enzyme to exoenzyme will be characterized. Electron microscopic localization of the membrane-bound penicillinase on the protoplast membrane will be attempted by immunological procedures.